/**
 * All rights reserved. Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.jivesoftware.smackx.pubsub;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Date;
import java.util.Iterator;
import java.util.UnknownFormatConversionException;

import org.jivesoftware.smackx.Form;
import org.jivesoftware.smackx.FormField;
import org.jivesoftware.smackx.packet.DataForm;

/**
 * A decorator for a {@link Form} to easily enable reading and updating of
 * subscription options. All operations read or update the underlying
 * {@link DataForm}.
 * 
 * <p>
 * Unlike the {@link Form}.setAnswer(XXX)} methods, which throw an exception if
 * the field does not exist, all <b>SubscribeForm.setXXX</b> methods will create
 * the field in the wrapped form if it does not already exist.
 * 
 * @author Robin Collier
 */
public class SubscribeForm extends Form {
	private static final SimpleDateFormat format = new SimpleDateFormat(
			"yyyy-MM-dd'T'HH:mm:ss.SSSZ");

	public SubscribeForm(DataForm configDataForm) {
		super(configDataForm);
	}

	public SubscribeForm(Form subscribeOptionsForm) {
		super(subscribeOptionsForm.getDataFormToSend());
	}

	public SubscribeForm(FormType formType) {
		super(formType.toString());
	}

	/**
	 * Determines if an entity wants to receive notifications.
	 * 
	 * @return true if want to receive, false otherwise
	 */
	public boolean isDeliverOn() {
		return parseBoolean(getFieldValue(SubscribeOptionFields.deliver));
	}

	/**
	 * Sets whether an entity wants to receive notifications.
	 * 
	 * @param deliverNotifications
	 */
	public void setDeliverOn(boolean deliverNotifications) {
		addField(SubscribeOptionFields.deliver, FormField.TYPE_BOOLEAN);
		setAnswer(SubscribeOptionFields.deliver.getFieldName(),
				deliverNotifications);
	}

	/**
	 * Determines if notifications should be delivered as aggregations or not.
	 * 
	 * @return true to aggregate, false otherwise
	 */
	public boolean isDigestOn() {
		return parseBoolean(getFieldValue(SubscribeOptionFields.digest));
	}

	/**
	 * Sets whether notifications should be delivered as aggregations or not.
	 * 
	 * @param digestOn
	 *            true to aggregate, false otherwise
	 */
	public void setDigestOn(boolean digestOn) {
		addField(SubscribeOptionFields.deliver, FormField.TYPE_BOOLEAN);
		setAnswer(SubscribeOptionFields.deliver.getFieldName(), digestOn);
	}

	/**
	 * Gets the minimum number of milliseconds between sending notification
	 * digests
	 * 
	 * @return The frequency in milliseconds
	 */
	public int getDigestFrequency() {
		return Integer
				.parseInt(getFieldValue(SubscribeOptionFields.digest_frequency));
	}

	/**
	 * Sets the minimum number of milliseconds between sending notification
	 * digests
	 * 
	 * @param frequency
	 *            The frequency in milliseconds
	 */
	public void setDigestFrequency(int frequency) {
		addField(SubscribeOptionFields.digest_frequency,
				FormField.TYPE_TEXT_SINGLE);
		setAnswer(SubscribeOptionFields.digest_frequency.getFieldName(),
				frequency);
	}

	/**
	 * Get the time at which the leased subscription will expire, or has
	 * expired.
	 * 
	 * @return The expiry date
	 */
	public Date getExpiry() {
		String dateTime = getFieldValue(SubscribeOptionFields.expire);
		try {
			return format.parse(dateTime);
		} catch (ParseException e) {
			UnknownFormatConversionException exc = new UnknownFormatConversionException(
					dateTime);
			exc.initCause(e);
			throw exc;
		}
	}

	/**
	 * Sets the time at which the leased subscription will expire, or has
	 * expired.
	 * 
	 * @param expire
	 *            The expiry date
	 */
	public void setExpiry(Date expire) {
		addField(SubscribeOptionFields.expire, FormField.TYPE_TEXT_SINGLE);
		setAnswer(SubscribeOptionFields.expire.getFieldName(),
				format.format(expire));
	}

	/**
	 * Determines whether the entity wants to receive an XMPP message body in
	 * addition to the payload format.
	 * 
	 * @return true to receive the message body, false otherwise
	 */
	public boolean isIncludeBody() {
		return parseBoolean(getFieldValue(SubscribeOptionFields.include_body));
	}

	/**
	 * Sets whether the entity wants to receive an XMPP message body in addition
	 * to the payload format.
	 * 
	 * @param include
	 *            true to receive the message body, false otherwise
	 */
	public void setIncludeBody(boolean include) {
		addField(SubscribeOptionFields.include_body, FormField.TYPE_BOOLEAN);
		setAnswer(SubscribeOptionFields.include_body.getFieldName(), include);
	}

	/**
	 * Gets the {@link PresenceState} for which an entity wants to receive
	 * notifications.
	 * 
	 * @return iterator over the list of states
	 */
	public Iterator<PresenceState> getShowValues() {
		ArrayList<PresenceState> result = new ArrayList<PresenceState>(5);
		Iterator<String> it = getFieldValues(SubscribeOptionFields.show_values);

		while (it.hasNext()) {
			String state = it.next();
			result.add(PresenceState.valueOf(state));
		}
		return result.iterator();
	}

	/**
	 * Sets the list of {@link PresenceState} for which an entity wants to
	 * receive notifications.
	 * 
	 * @param stateValues
	 *            The list of states
	 */
	public void setShowValues(Collection<PresenceState> stateValues) {
		ArrayList<String> values = new ArrayList<String>(stateValues.size());

		for (PresenceState state : stateValues) {
			values.add(state.toString());
		}
		addField(SubscribeOptionFields.show_values, FormField.TYPE_LIST_MULTI);
		setAnswer(SubscribeOptionFields.show_values.getFieldName(), values);
	}

	static private boolean parseBoolean(String fieldValue) {
		return ("1".equals(fieldValue) || "true".equals(fieldValue));
	}

	private String getFieldValue(SubscribeOptionFields field) {
		FormField formField = getField(field.getFieldName());

		return formField.getValues().next();
	}

	private Iterator<String> getFieldValues(SubscribeOptionFields field) {
		FormField formField = getField(field.getFieldName());

		return formField.getValues();
	}

	private void addField(SubscribeOptionFields nodeField, String type) {
		String fieldName = nodeField.getFieldName();

		if (getField(fieldName) == null) {
			FormField field = new FormField(fieldName);
			field.setType(type);
			addField(field);
		}
	}
}
